code: def __init__(self, capacity):
      self.capacity = capacity
      self.elements = [None for _ in range(capacity)]
      self.tree = [0 for _ in range(2 * capacity - 1)]
      self._ptr = 0
      self._min = 10
  
file_path: PARL/benchmark/fluid/Prioritized_DQN/proportional_per.py
imports: import numpy
label_desc: Use image node_id 1 to create a new SumTree object from inherited base classes: object with example: obj = SumTree(capacity)